A prototype pollution vulnerability allowed a crafted public webhook payload to inject attacker-controlled fields into workflow data during internal object copying. These fields could be surfaced and consumed as normal values by downstream built-in nodes.
Where a workflow combines a public webhook with action nodes that consume the resulting fields, an attacker could cause the workflow to act as a confused deputy — targeting unintended records or issuing outbound requests using the workflow owner's configured credentials.
The issue has been fixed in n8n versions 2.25.7, and 2.26.2. Users should upgrade to one of these versions or later to remediate the vulnerability.
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
{
"cwe_ids": [
"CWE-1321"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-16T19:00:41Z",
"nvd_published_at": "2026-06-23T17:17:06Z",
"severity": "MODERATE"
}